Unexpectedly Human Combat Tactics in Octopuses

In an investigation in which it has been possible to observe octopuses fighting among themselves, it has been discovered that they sometimes resort to using materials from their environment as weapons.

They collect what they can from the seabed and throw it at their adversary. They resort to this tactic against conspecifics and sometimes against other animals as well. This behavior is comparable to that of humans when we pick up stones from the ground to throw them at someone or something.

The team led by Peter Godfrey-Smith, from the University of Sydney in Australia, recorded the behavior of octopuses of the Octopus tetricus species in Jervis Bay, Australia, using underwater video cameras.

The study authors analyzed recordings from several days and identified 102 instances of octopuses throwing things at opponents. The octopuses involved were a dozen individuals, although it was not always possible to identify each one.

The octopuses collected materials such as silt, shells, pieces of algae and whatever they found from the seabed, and after lifting this load, they released it while using a jet of water from their siphon (an anatomical structure in the shape of a tube that can expel water at high speed) to propel the charge through the water, often managing to launch it several meters away.

To perform the launches, the octopuses had to move their siphon in an unusual position, suggesting that the behavior was deliberate.

An octopus (left) throws silt and bits of algae at its adversary. (Image: Godfrey-Smith et al., 2022, PLOS ONE. CC BY 4.0)

Throws made by individuals of both sexes were observed, but 66% of the throws were made by females.

About half of the releases occurred during or around the time of interactions with other octopuses, including mating attempts, and about 17% of the releases hit their target, hitting the recipient.

Octopuses can change their skin coloration, with dark colors generally associated with aggression, and the researchers found that individuals sporting a dark color tended to throw things with more force and were more likely to hit with them. to another octopus

Octopuses hit by the thrown material tended to alter their behavior, crouching or extending their tentacles in the direction of the octopus that had thrown things at them.

What has been observed shows that octopuses are capable of throwing objects in the desired direction, with enough aim to hit the individuals against whom they have thrown what they have picked up on a significant percentage of occasions.

This is the first time that this behavior of picking up objects and throwing them at an opponent has been scientifically documented in octopuses.

This behavior had only previously been observed in a few non-human animals.

The study has been published publicly in the academic journal PLoS ONE. The work reference is as follows: Godfrey-Smith P, Scheel D, Chancellor S, Linquist S, Lawrence M (2022) In the line of fire: Debris throwing by wild octopuses. PLoS ONE 17(11): e0276482. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0276482 (Font: NCYT by Amazings)